48 lines
946 B
C
48 lines
946 B
C
/* vi: set sw=4 ts=4:
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*
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* truncate.c - set file length, extending sparsely if necessary
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*
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* Copyright 2011 Rob Landley <rob@landley.net>
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*
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* Not in SUSv4
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USE_TRUNCATE(NEWTOY(truncate, "<1s#|c", TOYFLAG_BIN))
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config TRUNCATE
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bool "truncate"
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default y
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help
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usage: truncate [-c] -s file...
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Set length of file(s), extending sparsely if necessary.
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-c Don't create file if it doesn't exist.
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-s New size
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*/
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#include "toys.h"
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DEFINE_GLOBALS(
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long size;
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)
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#define TT this.truncate
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static void do_truncate(int fd, char *name)
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{
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if (fd<0) return;
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if (ftruncate(fd, TT.size)) {
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perror_msg("failed to set '%s' to '%ld'", name, TT.size);
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toys.exitval = EXIT_FAILURE;
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}
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}
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void truncate_main(void)
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{
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int cr = !(toys.optflags&1);
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// Create files with mask rwrwrw.
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// Nonexistent files are only an error if we're supposed to create them.
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loopfiles_rw(toys.optargs, O_WRONLY|(cr ? O_CREAT : 0), 0666, cr,
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do_truncate);
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}
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